A field effect transistor of this type is known as a junction field effect transistor (JFET). One advantage of this type of field effect transistor is the low noise. In conjunction with an integrated circuit, these field effect transistors are used in particular in power applications. One aim of these applications is to provide a transistor which combines a high breakdown voltage with a low resistance in the on state and requires a small area. Special production processes are customary for the JFETs with epitaxial layers.
US 2002/0132406 A1 discloses a vertical high voltage transistor comprising multiple depletion layer conduction channels, which transistor contains zones that are buried in planes of an n-type well lying one above another.
U.S. Pat. No. 6,153,453 discloses a method for producing a junction field effect transistor in conjunction with further MOS transistors which are used at low voltages and frequencies. The low voltage process used for the MOS transistors is used with small changes for the production of the junction field effect transistor.